This paper looks at the reasons for and results of vertical integration, with specific regard to its possible effects on market power as proposed in the theoretical literature on foreclosure. It uses a rich plant-level data set of cement and ready-mixed concrete producers that spans several decades to perform a detailed case study. There is little evidence that vertical foreclosure effects are ...

We present the results of displacement flows different Newtonian and Herschel–Bulkley non-Newtonian fluids in a new-developed eccentric Hele–Shaw cell with dynamic similarly to real field wellbore annulus during primary cementing. The possibility tracking interface between using particles intermediate or neutral buoyancy is studied. behaviors movements sizes densities against vertical flow stro...

The article presents the results of research on influence enzymatic and oxidizing agents polymers used in drilling mud technology. calcium hypochlorite, urea peroxide, sodium persulfate, amylase cellulase. This allowed us to determine optimal concentrations these order reduce rheological parameters muds. ability enzymes oxidants decompose colloids composition muds was determined basis measureme...

It is difficult to obtain high quality samples of natural material covering a range of densities and degree of cementation, so study on the sample preparation techniques with similar mechanical properties of natural samples are very important. Experiments were carried out to study the effects of cementation of different materials on the mechanical properties of calcareous sand, e.g., the effect...

a compressive strength of 2,200 psi and the other with a compressive strength of 3,500 psi, were the most satisfactory for cementing temporary restorations. The data collected, however, were not sufficient in quantity to differentiate between the two cements. There was the possibility that one or the other of the two cements might prove superior, and this investigation was undertaken to collect...

Large vibrating plates are used as thunder sheets in orchestras. We have extended the use of flat plates by cementing a flat panel electroacoustic transducer on a large brass sheet. Because of the thickness of the panel, the output is subject to nonlinear distortion. When combined with a real-time input and signal processing algorithm, the active brass plate can become an effective musical inst...

Study Design: A prospective study of clinical and radiographic results after vertebral body stenting (VBS) for treatment of osteoporotic vertebral compression fractures (VCFs). Objectives: To evaluate the effectiveness of stentoplasty as a new technique to treat symptomatic VCFs. Background Data: Conventional balloon kyphoplasty is a procedure meant to treat osteoporotic and/or cancer related V...

cementing is an essential part of every drilling operation. protection of the wellbore from formation fluid invasion is one of the primary tasks of a cement job. failure in this task results in catastrophic events, such as blow outs. hence, in order to save the well and avoid risky and operationally difficult remedial cementing, slurry must be optimized to be resistant against gas migration phe...